Two important features are missing for a first feature complete stable release:

The first one is that our current dictionary based spectral implementation has reached its limits when building support for Machado et al. (2010): attempting to alter the domain or range of a SpectralPowerDistribution is difficult. With that in mind, we have started to work on a new alternative implementation where data is exposed as a continuous function modeled using an interpolating function encapsulated within an extrapolating function: #335.

The second is support for metadata inside the API. Most of the codebase adopts definitions/functions over classes to stay clean and lean, the aforementioned spectral implementation being a notable exception. As a consequence, it is hard to implement a non-intrusive classifying mechanism, provide usable hints on functions domain/range or create an auto-conversion layer. We have considered multiple ways of providing the necessary metadata, e.g. experimental/medatada* branches, and decided that the true elegant solution was through docstrings.

The following example showcases the current implementation, defining metadata for parameters, returns and the definition by using the notes section:

There is one caveat though: running Python with -OO argument will optimize the bytecode and trim the docstrings and as a result preventing metadata usage. This is an edge case we are aware of and it will be advertised.

These two features are consequential and taking a fair amount of time to implement and test. They will also introduce backward incompatible changes.

colour-science.org has been quiet for a while
however, it does not mean nothing happened. Colour 0.3.9
and Colour - HDRI 0.1.2
were released today and last week, concluding a major collaborative effort, the ACES
community addressed an important feedback paper to the Academy leadership.